Rotary turning attachment equipped with at least two tools

ABSTRACT

The invention concerns an attachment ( 1 ) comprising a radial sliding track ( 103 ) for each slide ( 2 ), recessed in the attachment body. Two semicircular plates ( 4, 5 ) maintain the slides in the sliding track ( 103 ) and guide them. The slides are locked by screws ( 18, 19 ) operating by deforming the corresponding semicircular plate ( 4, 5 ). The displacement of a slide is obtained by a micrometric screw ( 12 ) operating on a nut integral with the slide.

The present invention relates to a rotary turning attachment with atleast two tools, comprising a cylindrical body designed to be mounted onthe spindle of a machine tool, at least two slides designed to moveradially with respect to the axis of rotation of the body, each of theslides being secured to a removable tool holder.

The present invention relates more particularly to cylindrical turningattachments equipped with interchangeable tip holders for standard ISOtips. These attachments are intended for the spindles of transfermachines and special machines. For many years, this type of machine hasbeen suited only to the mass production of parts that can be machinedrelatively easily. The increasingly stringent demands for precision andproductivity, the constant efforts to reduce production costs and theconsiderable advances made in cutting tips means that it can now beenvisaged for these machines to be used for moderate or even shortproduction runs, and materials which are more difficult to machine.Production changes are far more frequent. It is thus necessary todrastically reduce the unproductive time by reducing the setting time,which is still relatively lengthy. Often, the machining of a difficultmaterial and tight tolerances entail frequent interventions to makemicroadjustments or change the cutting tools or tips.

Most manufacturers of transfer machines have their own system of toolingand the users have barely any choice and have to tolerate theinconveniences of this situation. Often too, the very restricted amountof space available limits the use of standardized conventional orquick-change tool holders.

There is a real need for improvement and rationalization; even thoughusers are doing the best that they can, they are still, however, waitingfor rational tooling that meets their needs.

The object of the present invention is to propose a very compact rotaryturning attachment which is suited to customary and standardizedmachine-tool spindles. Thus, for example, in the case of the attachmentset out according to the invention, the outside diameter is 42, 50, 63or 83 mm with a working diameter between the cutting edges of the tipsthat can vary between 2 and 48 mm. Larger attachments are obviously alsofeasible.

The rotary attachment according to the invention is one wherein thecylindrical body comprises, on one plane face, one slideway per slide,formed in a recess running along a radius of said plane face anddesigned to allow the slide to move; at least two plates are attachedremovably to said face of the body, so as to hold the slides in therespective slideway in the direction of the axis of rotation of theturning attachment; said attachment comprises at least two housings,each running from the lateral surface of the cylindrical body inward,parallel to said slideway, said cylindrical housings being designed totake the micrometer screws each of which controls the individualmovement of one slide; and said cylindrical housings each open into ahousing of larger dimensions communicating with the correspondingslideway, the latter housing allowing a nut secured to a slide to behoused and moved therein, the threaded part of a micrometer screw beingengaged in said nut.

The advantage of this turning attachment is that in spite of its smallsize, its relatively small volume is able to house means which allow themovement of the cutting tools to be set precisely.

According to one alternative form, when the need is there and dependingon the diameter of the attachment, a concentric bore allows a cuttingtool to be attached coaxially with a screw arranged radially in thebody.

Upward of a certain size, a taper nut can be housed at the center and,in collaboration with a taper collet placed directly in the spindle ofthe machine on which the attachment is mounted, allows a tool to beattached coaxially using standardized double taper collet chucks (DIN6499) or the like.

According to another alternative form, the slide is locked by thedeformation of the plates using a binding screw acting on the part ofthe slide located in the slideway, the deformation being facilitated byan appropriate clearance in the face of the body under each semicircularplate. The plates may also be locally thinned in order to adapt theirflexibility.

According to another alternative form, the micrometer screws controllingthe movement of the slide are held in place by pins engaged in a groovenear to the head of the corresponding screw.

According to another alternative form, the slides are designed also toallow axial adjustment of the tool supported by a tool holder.

As a preference, the slides are equipped with a toothed face facingaxially so that interchangeable tool holders equipped with an oblongopening running axially and allowing the attachment member to pass canbe attached thereto.

According to a preferred alternative form, the tool holder is equippedwith an axial adjustment member which moves parallel to the direction ofadjustment, pressing against a surface of the slide perpendicular tosaid direction of travel.

As a preference, the attachment member and the axial adjustment memberare, on the one hand, an attachment screw and, on the other hand, aself-locking thrust screw incorporated into the tool holder.

It is obvious that a key or mutual nesting of the two flat faces of theslide and of the tool holder may just as easily constitute axialguidance for adjustment and positioning. However, to produce this shortand rigid construction in a very tight space without reducing theability of the slide and of the tool holders to withstand the cuttingforces, the risks of vibration and centrifugal force at high speed, ithas proved necessary to keep carefully sited ribs which keep the crosssection of the two components high enough.

What is more, the axial adjustment thrust screw is incorporated into thetool holders at a suitable location so that by butting against the slideit contributes to the rigidity of the two elements assembled. Anotherspecial feature of this construction automatically allows the thrustscrew to press firmly in the axial direction against the slide as thetool holders are clamped. Specifically, in an alternative form, the faceof the tool holders on which the head of the attachment screw acts isinclined slightly so that by turning it to the right to lock it, theface of the head of the screw preferably acts on the side via which thisgenerates a resulting force which also axially presses the tool holderagainst the slide via the axial adjustment thrust screw. Thischaracteristic therefore additionally provides an increase in rigidity,an improvement in the precision of the axial adjustment whileeliminating any risk of slight backward movement of the tool holder withrespect to the slide while it is being locked by the transverseattachment screw. The latter can protrude beyond the slide and thus befitted with an additional safety nut, depending on the dimensions of theattachment, of course.

These novel particular features of the construction of these attachmentsoffer ease of adjustment and at the same time machining performancewhich are unique to attachments as compact as this with such acapability. Such attachments have a working capability of a maximumdiameter of 48 mm for an attachment outside diameter of 83 or acapability of 22 mm diameter for an outside diameter of 52 mm, forexample.

The invention will be described in further detail with the aid of theappended drawing which illustrates one embodiment according to theinvention.

FIG. 1 is a view from beneath of the turning attachment with two slides.

FIG. 2 is a side view of the same attachment.

FIG. 3 is a side view partially in section of the attachment of FIG. 2rotated through 90° about the axis of rotation.

FIG. 4 is a side view of the slide.

FIG. 5 is a side view rotated through 90° with respect to FIG. 4 andpartly in section, and

FIG. 6 is a view from the right of FIG. 4.

FIG. 7 is a view similar to that of FIG. 3, of an attachment with fourslides.

The turning attachment comprises a body 1 formed of a cylindrical part10 with, at one end, a bore 101 equipped with means for assembling theattachment with the spindle of the machine tool. Means 102 allow it tobe grasped in a tightening tool, while on the other face, twoessentially rectangular recesses stretch along one diameter of the faceof the cylinder forming a slideway 103 inside which two slides 2 and 3slide.

If the turning attachment were to have other slides, the slideways wouldextend out symmetrically from the center of the attachment.

The face with the slideway 103 is equipped with two semicircular coverplates 4 and 5 partially covering the slideway 103 to allow the slides 2and 3 to be held in the axial direction. The plates 4 and 5 are screwedto the attachment 10 by screws 6 once the slides 2 and 3 have beenfitted.

In the case of an attachment with four slides, four plates would beused, each plate acting on two slides.

We shall now describe the slides with the aid of FIGS. 4 to 6. We shallconfine ourselves to a description of the slide 2 and, betweenparentheses, on said figures, we have indicated the references of thesecond slide 3. The slide 2 comprises a head 20 of rectangular shape,the dimensions of which allow it to fit in the slideway 103 in theattachment 10 of the cylindrical body. The head 20 (see FIG. 5) has twoperpendicular housings 201 and 202. The first is tapped and is able tohouse a screw 20 intended to lock a nut 21 in the housing 202. When theattachment is one whose body 1 has an additional bore concentric withthe axis for housing a tool, that face of the head of the slide whichfaces toward the axis of the attachment has a rounded clearance 203(FIG. 6) in order to increase the possible travel of the slide.

The slide has a projection for retaining the tool holders, and thisprojection consists of a part of a certain thickness in the shape of a L204 and a second part 205 of lesser thickness in which a tapping 206allows a screw 9 to be used to attach a tool holder 7, or 8. In theory,the tool holder bears tips 71, or 81. The individual movement of eachslide is achieved by a micrometer screw 12, or 13, equipped with agroove 121 and with a threaded screw body 123 fixed in a housing 14, or15. The housings 14 and 15 are arranged symmetrically with respect tothe axis of rotation of the body 10 and stretch from the lateral surfaceof the cylindrical body toward the center and end in a housing of alarger size 16, or 17. These housings 16 and 17 are in communicationwith the slideway 103 over a certain length to allow the nut 21, or 31,to pass and move while the position of the respective slide is beingset.

Each micrometer screw 12, or 13, is fixed in said housing by means oftwo pins G which engage in the respective grooves 121 and 131.

To achieve the best operation, the attachment may be assembled asfollows: first of all, the nuts 21, 31 are introduced into the slides 2,3 in the undrilled and untapped condition, and are locked in place usingscrews 207 and 307.

Next, the slides 2 and 3, with their nuts, are engaged in the slideways103 in the body 10 of the attachment and the semicircular plates 4 and 5are attached using their attaching screws 6; the locking screws 18 and19 are also fitted and the slides are locked in the outermost position.

Next, the drillings and tappings may be made in the nuts 21 and 31,centered and aligned exactly on the bores 14 and 15, thus ensuring thatthese are perfectly coaxial with the micrometer screws 12 and 13.

Then, after cleaning, the micrometer screws may be screwed into the nuts2 and 3 as far as a position in which the grooves 121 and 131 align withthe holes in the body 10 which are intended for the locking pins G, andthe locking pins are driven in.

The various components can be marked so that they can be returned totheir original position if ever the device is dismantled andreassembled.

Thereafter, having set the position of the cutting tools using themicrometer screws 12 and 13, the slides are locked in position by actionon the two nuts or screws 18 or 19, which slightly deform thesemicircular plates, which deformation is made easier by the clearances104 formed on the face of the body thus clamping the slides in theslideway. A thinning of the plates may increase their flexibility ifdesired. The graduated divisions on the face of the head of themicrometer screws makes the setting easier to read. Microadjustments mayalso be made using a comparator showing the precise actual movement ofthe slides. In many instances, the attachment is preset and then mountedon the machine spindle.

If the diameter of the attachment so permits, a central bore is made, inwhich an additional tool may be attached, for example using one or moreradial screws, not depicted.

Referring now to FIG. 7, we have depicted a turning attachment in a viewsimilar to that of FIG. 3, except that this attachment is of far greaterdiameter and is equipped with four slides, three of which can be seen inthis figure.

We are not going to describe the body of the attachment again, and wehave merely indicated a few references which are the same as those ofFIG. 3, except that they carry a prime symbol.

As regards the elements which truly differ from those of the attachmentof FIG. 3, and apart from the fact that the attachment is designed forfour slides, these are the slides themselves because they are equippedwith means for allowing axial adjustment in addition to radialadjustment.

Another novelty is the fact that the diameter of this attachment allowsa double taper collet chuck 90, fixed in a taper collet 91 of thespindle of the machine on which the attachment 10′ is to be attached tobe provided coaxially with the axis of said attachment. Thus, by usingan appropriate nut in the body of the attachment, another cutting toolcan be mounted coaxially with this attachment. This type of fitting witha double taper collet chuck 90 is known and standardized. It would alsobe possible to use another type of fitting if the diameter of theattachment allows this fitting to be housed coaxially with theattachment.

We now return to the description of the slide with axial adjustment. Inthis FIG. 7 we can see three different views of three different slides,but we are going to use the same references for the same elements on allthree slides, said elements being identical even though they do notphysically relate to the one same slide.

The slide referenced with the reference 900 has a head which glides inthe corresponding slideway of the turning attachment and which ispractically identical to the one described previously, and we shalltherefore refrain from describing it. The slide has a projection forholding tools with an approximately L-shaped cross section. A first part901 has a greater thickness and provides guidance as the tool holdermoves and is of relatively narrow width, whereas another part 902 isequipped with a set of teeth 903 on one face. The toothed surface 902 ofthe slide 900 has passing it through it a hole 904 which may or may notbe tapped depending on the size of the attachment, for the passage of afastening screw 905. Specifically, if the dimensions of the attachmentso allow, as is the case in FIG. 7, use is made of a relatively longscrew at the end of which a nut 906 secures the assembly. If thedimensions do not allow the screw to extend this far and the use of thenut, the passage 904 will be tapped and the screw 905 will be screwedinto said tapping.

The tool holder 907 also has the overall shape of a L, one branch 908 ofwhich has a face for contact with the face 903 of the slide and istoothed with a complementing set of teeth to allow precise guidance. Thebranch bearing this toothed surface has an oblong opening 909, thedimensions of which delimit the maximum axial movement of the toolholder on the slide. The part of the second branch of the L 910 isequipped with an adjusting screw 911 housed in an axial tapping 912(with respect to the axis of the head of the slide) and this screw buttsagainst a surface 913 perpendicular to the set of teeth 903. This screw911 is self-locking by means of a screw 914 arranged in a tapped housingperpendicular to the housing 912.

The cutting tool 915 is attached to the end of the tool holder byconventional means. When the axial movement of the tool holder is beingadjusted, the screw 905 is slackened and the screw 911 is used to placethe tool holder in the desired position in such a way that the screw 911butts against the surface 913 of the slide, then the screw 905 istightened again in the direction of the arrow as shown in the figure, toobtain an assembly which is as compact and rigid as possible.

According to a preferred alternative form, the outer surface of the leg908 of the tool holder is slightly inclined so that when the screw 905is tightened the tool holder is pushed axially toward the clamping head,which makes sure that the tool holder presses against the slide, via theaxial adjusting screw 911 of course, thus increasing the rigidity of theassembly and improving the precision of the axial setting because thateliminates any risk of backward movement of the tool holder with respectto the slide while the transverse attaching screw is being locked.

What is claimed is:
 1. A rotary turning attachment with at least twotools, comprising (a) a cylindrical body intended to be mounted on aspindle of a machine tool and having a lateral surface and an axis ofrotation; (b) at least two slides that move radially with respect to theaxis of rotation of said cylindrical body, each of the slides beingsecured to a removable tool holder, wherein the cylindrical bodycomprises, on one plane face, one slideway per slide, formed in a recessrunning along a radius of said plane face allowing the slide to move;(c) at least two plates attached removable to said face of the body, soas to hold the slides in the respective slideway in the direction of theaxis of rotation of the turning attachment; said attachment comprises atleast two cylindrical housings, each running from the lateral surface ofthe cylindrical body inward, parallel to said slideway, said cylindricalhousings being designed to receive a micrometer screw each of whichcontrols the individual movement of one slide; and said cylindricalhousings each open into a housing of larger dimensions communicatingwith the corresponding slideway, the latter housing allowing a nutsecured to a slide to be housed and moved therein, and a threaded partof the micrometer screw being engaged in said nut.
 2. The turningattachment as claimed in claim 1, wherein the body is equipped with abore that is concentric with the axis of the body and intended for theattaching of another tool.
 3. The attachment as claimed in claim 2,wherein a taper nut is housed in the concentric bore and, incollaboration with a taper collet placed in the spindle of the machineon which the attachment is mounted, allows a tool to be attachedcoaxially with the attachment using double taper collet chucks.
 4. Theattachment as claimed in claim 1, wherein the body is equipped withmeans for locking the slides after they have been adjusted, said meansconsisting in one locking screw per slide each acting on one of theplates so as to lock the slide in place by deformation of said plateafter said screws have been tightened, in accordance with the clearancesformed on the body of the attachment.
 5. The attachment as claimed inclaim 2, wherein the body is equipped with means for locking the slidesafter they have been adjusted, said means consisting in one lockingscrew per slide each acting on one of the plates so as to lock the slidein place by deformation of said plate after said screws have beentightened, in accordance with the clearances formed on the body of theattachment.
 6. The attachment as claimed in claim 3, wherein the body isequipped with means for locking the slides after they have beenadjusted, said means consisting in one locking screw per slide eachacting on one of the plates so as to lock the slide in place bydeformation of said plate after said screws have been tightened, inaccordance with the clearances formed on the body of the attachment. 7.The turning attachment as claimed in one of claims 1 to 4 or 5 to 6,wherein the micrometer screws are locked in place in their respectivehousing using two pins engaged in a groove located near to themicrometer screw head.
 8. The attachment as claimed in one of claims 1to 4 or 5 to 6, wherein the slides allow axial adjustment of the toolsupported by a tool holder.
 9. The attachment as claimed in claim 8,wherein each slide is equipped on one face with a set of teeth intendedto collaborate with a mating set of teeth belonging to one face of thetool holder, and said face of the tool holder has an oblong openingrunning axially through which a member for attaching the tool holder tothe slide passes.
 10. The attachment as claimed in claim 9, wherein thetool holder is equipped with a member for axial adjustment actingparallel to the direction of adjustment by pressing against a surface ofthe slide perpendicular to said direction of adjustment.
 11. Theattachment as claimed in claim 10, wherein the member for attaching isan attachment screw, and the surface of the tool holder against whichthe head of said attachment screw presses is inclined so that upontightening, the tool holder is clamped against the surface of the slidevia the member for axial adjustment also.
 12. The attachment as claimedin claim 9, wherein the member for attaching is an attachment screw, andthe surface of the tool holder against which the head of said attachmentscrew presses is inclined so that upon tightening, the tool holder isclamped against the surface of the slide via the member for axialadjustment also.